Researchers evaluated the use of azathioprine and glucocorticoids as remission induction therapy for nonsevere SNVs.

Adding azathioprine to glucocorticoid therapy has no significant benefit for patients with nonsevere systemic necrotizing vasculitides (SNVs), a population that is still in need of alternative first-line therapies, according to a study published in Arthritis & Rheumatology.

In the first double-blind, randomized controlled trial of its kind evaluating the use of azathioprine and glucocorticoids as remission induction therapy for nonsevere SNVs, including eosinophilic granulomatosis with polyangiitis (Churg-Strauss) (EPGA), researchers allocated 51 patients with EPGA, 25 patients with microscopic polyangiitis (MPA), and 19 patients with polyarteritis nodosa (PAN) to receive oral azathioprine 2 mg/kg/day (maximum 200 mg/day) (n=46) or placebo (n=49) for 12 months. All patients received glucocorticoids concomitantly, which were tapered gradually over 12 months. After discontinuing azathioprine or placebo, researchers monitored patients until the primary end point of the combined rate of remission induction failure and minor or major relapse at month 24.

By 24 months, 47.8% of patients in the azathioprine group had remission induction failure or relapse compared with 49% of patients in the placebo group (P =0.86). Secondary end points, such as initial remission rate (95.7% vs 87.8%), total relapse rate (44.2% vs 40.5%), and glucocorticoid use were similar between patients who received azathioprine and placebo, respectively. For patients with EPGA, the primary end point (48% vs 46.2%) and the rate of asthma/rhinosinusitis exacerbations (24% vs 19.2%) were also comparable between the azathioprine and placebo groups, respectively. Rates of adverse events, hospitalizations, and outpatient visits were similar between the groups.

The researchers concluded that, “the results of this study demonstrate that addition of [azathioprine] to glucocorticoids to induce remission of nonsevere EGPA, MPA, or PAN does not lower the absolute risk of therapeutic failure or relapse vs placebo, does not lower glucocorticoid use, and does not lower EGPA patients' rate of asthma/rhinosinusitis exacerbations.”